Process for the in situ sealing of soil surrounding underground conduit breaks

ABSTRACT

A process for sealing soil adjacent to underground conduit breaks through the use of surfactant-stabilized latex emulsion wherein the sealing phenomena can be made to occur at varying penetration depths therein forming a seal against fluid flow.

Umted States Patent 1 1 1111 3,727,412

Marx et a]. 51 Apr. 17, 1973 541 PROCESS FOR THE IN SITU SEALING3,145,773 8/1964 Jorda et al. ..166/294 x ()F SOIL SURROUNDING 3,227,572H1966 Rundle et a]. ..6l/36 x UNDERGROUND CONDUIT BREAKS 3,312,2964/1967 Paramore et a]. ..l66/294 X 3,443,640 5/ 1969 Klein ..l66/294[75] Inventors: John W. Marx; Jr. Bowman, both of Bartlesvlne Okla'Primary ExaminerDavid J. Williamowsky [73] Assignee: Phillips PetroleumCompany, Bar- Assistant Examiner-David H. Corbin tlesvme, Okla-Attorney-J. Arthur Young et al. p

[22] Filed: Aug. 16, 1971 [57] ABSTRACT [211 App]' 172279 A process forsealing soil adjacent to underground 521 US. Cl ..61/36 R, 138/97,166/294 conduit breaks through the use of surfactant-stabilized [51]Int. Cl. ..E02d 3/12 latex emulsion wherein the sealing phenomena can be[58] Field of Search ..6l/36 R; 138/97; made to occur at varyingpenetration depths therein 6 /294 forming a seal against fluid flow.[56] References Cited UNITED STATES PATENTS 14 Claims, No Drawings2,121,036 6/1938 Irons ..6l/36 X PROCESS FOR THE IN SITU SEALING OF SOILSURROUNDING UNDERGROUND CONDUIT BREAKS This invention relates to aprocess for the in situ sealing of soil adjacent to underground conduitbreaks. In a more particular aspect, this invention relates to the insitu sealing of soil surrounding underground conduit breaks through theinjection therein a surfactant-stabilized emulsions. In yet anotheraspect, this invention is directed to a process for reducing thepermeability of soil to fluid flow. This invention has particularapplications where it is desirable to stop the passage of fluid flowthrough the walls of an underground conduit or the soil adjacentthereto.

Repairing cracks and leaks in underground conduits whether they be forwater, sewage, general fluid transportation, or utilities, is anexpensive and time-consuming operation. It is the usual procedure toremove the soil, rocks, or other materials surrounding the leakingconduit and patch the cracks, if possible, or remove the cracked ordamaged conduit section completely. Other repair procedures haveincluded applying leak clamps to defective joints and split sleeves tostraight sections, or surrounding the defective section with concrete orsimilar materials.

Repairs to a defective system have also been made by applying a concretelining to the inner surface of the 1 conduits. This method, althougheffective, requires special equipment and reduces the capacity of thesystem. Another method of temporarily reducing leakage which has beenproposed in utility conduits is the application of a waxy solution whichswells the packing materials in joints and other problem areas.

Leaks in conduits which transmit anhydrous fluids, such as natural gas,have also been found particularly difficult to reduce for anysubstantial length of time. Materials used to stop the leakage havetended to dry out and crack, thus preventing repairs of any permanence.Also, weather conditions such as freezing or thawing affect mostsealants.

The aforementioned methods for repairing underground conduit leaks havebeen aimed at both the reduction of fluid flow from the conduit as wellas fluid flow into the conduit. Heavy rainfall, for example, can invadethe underground conduit systems mainly through faulty joints and cracks,producing unwanted problems such as electrical shorting, conduit fluidcontamination as well as overloading of conduit capacities. These samebreaks also permit escape of conduit fluid in dry weather.

A commonplace and troublesome underground conduit application is in thetransporation of sewage water which can escape into the surrounding soilto create sanitation problems. On the other hand, if the pressure of thewater in the soil surrounding the sewer pipe is sufficiently great, thewater moves into the sewer conduit. In the latter case, the excessamount of water in the sewer conduit overburdens the facilities ofsewage disposal plants, making it extremely difficult to process thesewage properly. Although the above emphasizes the use of the processdescribed herein primarily for the repair of leaking conduits used totransport sewage, the process is not so limited. The described processis applicable to the repair of leaks in any ceramic, concrete, metal,and the like conduits which carry fluids, utility cables, phone cables,and the like.

It is an object of this invention to provide an in situ process forsealing the adjacent soil, around an underground conduit break therebyinhibiting fluid flow therefrom. It is another object of this inventionto provide a process for sealing the soil adjacent to undergroundconduit breaks thereby preventing infiltration of exterior fluids.

In accordance with this invention there is provided a process forsealing the soil adjacent to underground conduit breaks to preventinfiltration of exterior fluids or escape of conduit fluids. A portionof underground conduit upstream and downstream from the break is blockedoff and flushed. A surfactant-stabilized latex or asphalt emulsion isthen injected into the blocked off portion under pressurized conditions.The amount of surfactant utilized is adjusted to a threshold valuebefore injection of emulsion material into the conduit and preventingcoagulation in the conduit itself. The surfac tant-stabilized emulsionis maintained under pressurized conditions within the conduit portionfrom 15 minutes to 24 hours depending upon the insight to conditions.Normally the emulsion is maintained in the conduit until further sealantaddition is found to be unnecessary. Multiple sealant treatment stepscan be achieved when required by insitu conditions.

Surfactant-stabilized particle dispersions are also suitable means forthe process of our invention. The insight to sealing of soil adjacentthe underground conduit breaks may be accomplished by using, forexample, carbon black dispersions, asphalt emulsions, colloidal sulfur,and the like. Commercial dispersions of asphalt and water are normallymade for highway treatment using either anionic or cationic surfactantstabilizers. Theseare designated in highway specifications as SS (slowsetting) and FS (fast setting) emulsions, respectively. Both typesusually have average particle diameter of less than 5 microns, but theyalso contain terminal particles of from 30 to about 50 microns indiameter, therefore being too large to penetrate most porous soil media.

The surfactant-stabilized emulsions of this invention, upon entering thesurrounding soil adjacent to the underground conduit break, coagulateunder controlled conditions ranging from about 0.1 inch to several feet.The aforementioned coagulation is the result of the surfactant beingadsorbed onto the internal soil surfaces therein upsetting thesurfactant coagulation balance. By proper adjustment of the surfactantbalance, the sealing phenomena of this invention can be freely ad justedas to depth, soil type, and fluid flow problems.

A threshold stability emulsion is herein defined for the purposes ofthis invention as being one having sufficient surfactant stabilizationagent therein to maintain the emulsion without coagulation occurring.Such a threshold stabilized emulsion is easily coagulated by the removalof a small portion of the included surfactant stabilizing agents. Forexample, when a surfactantstabilized emulsion invades a porous medium,the leading edge of the invasion front is progressively destabilized byadsorption or chemisorption of surfactant on the internal mineralor-soil surfaces. The destabilized primary particles (1) may combinewith each other to form larger aggregates, i.e., secondary particles,and/or (2) they may be deposited as an adherent layer on the mineralsurface. In either case, the precipitated particles reduce thepermeability of the porous matrix, and

these particles which adhere strongly to the mineral surface also serveas a binder for unconsolidated media.

in order to apply this process at its greatest efficiency, it isessential that the particles be small enough to essentially penetratethe pore openings in the adjacent soil. This permits sealing incontrolled depths. Large particles would simply be filtered out at thesoil surface and subsequently backflowed into the line by invadingexterior fluids. Once deposited, the emulsion particles of thisinvention are not redispersed by subsequent exterior flooding. For thepurposes of this invention, the physical interactions betweensurfactant-stabilized emulsions and the porous media are governed byfactors listed below:

1. primary particle size relative to pore size;

2. surfactant type;

3. surfactant concentration;

4. particle solids concentration; and

5. types of particle emulsions The particle size criterion is determinedby the terminal (largest) particles. If the terminal particles approachor exceed the size of the largest pores in the porous medium, theparticles will be filtered out mechanically at the entry face, withlittle or no penetration to the porous matrix. It is the terminalparticle size, not the average or median size, that determines whetherthe particle system can penetrate a given porous medium. For sealingsoil adjacent to conduit breaks, it is desirable to keep the maximumprimary particle size within the limits as given in Table I hereinbelow,in order to secure deep penetration at low pressure gradients.

TABLE 1 Preferred Sealant Particle Porous Medium Size RangeClay,fine.dust Up to 0.5 micron Silt, very fine sand Up to l micron Finesand Up to 3 microns Medium sand Up to 5 microns Coarse sand Up tomicrons Very coarse sand, fine gravel Up to 30 microns it should benoted that any emulsion can contain a .few outside freaks, secondaryaggregates, extraneous debris, microbubbles, and the like. Normallythese isolated exceptions constitute a negligible fraction of theoverall particle solids volume and are not regarded as characteristicterminal particles.

Stabilizing surfactants fall into three broad categories: l) nonionic,(2) anionic, and (3) cationic. Although there are wide differences insurfactant behavior within each grouping, the chemical reactivity issimilar for all members of any one category. In general, the nonionicsurfactants do not react chemically with soil minerals; therefore theirsoil reaction is oneof physical adsorption rather than chemisorption.For this reason, nonionic surfactants are preferred for treating finelydivided soil particles, where deep penetration is desired and where themineral compositions of the soil porous inner surfaces vary frompointto-point.

Anionic surfactants do not react chemically with clay or silicasurfaces, but they do precipitate on contact with the calcium,magnesium, and iron ions found in most wet soils. Chemisorption ofanionic stabilizers can be tolerated for sealing coarse sands or finegravel fill adjacent to sewer line breaks, but they are undesirable fortine soil applications. Exemplary of suitable anionic surfactantssuitable for the process of this invention are as follows: sodium laurylsulfate, sodium stearant, sodi um oleate, sodium linolenate, cetylsulfate, and the i like.

Cationic surfactants react with most silica and clay surfaces, and withmost negative ions, found in many ground waters. The massivechemisorption results in limited penetration of the porous soil matrixregardless of the particle size of the dispersion. Cationic surfactants,therefore, are less desirable than anionic or nonionic surfactants asfor the purposes of this invention.

Nonionic stabilizing surfactants are preferred for the purposes of thisinvention due to maximum penetration ability, but anionic and cationicsurfactant stabilizers are not excluded from the scope of thisinvention. Suitable nonionic surfactants which are commerciallyavailable can be selected for example, from any of the nonbiodegradablenonionic surfactants found in Mc- Cutcheons detergents and emulsifiers1970 annual, published by the Allured Publishing Corporation, 45 NorthBroad Street, Richwood, NJ. 07450. Exemplary of the aforementionednonionic surfactants suitable for the process of this invention are asfollows.

nonylphenoxypoly(ethyleneoxy)ethanol,

octyl phenoxypoly( ethyleneoxy)ethanol,

alkyl aryl polyether alcohol, polyglycol ester,

fatty alkylol amide condensate, RNH(CH,CH,O),,

ethoxylated alkenylamine, and the like.

Each specific particle-surfactant combination has a minimum (threshold)concentration of surfactant required to maintain bulk stability. If, forany reason, the surfactant content drops below this threshold value, thesuspended particles will coagulate out of the bulkcarrier or waterphase. The threshold surfactant requirement depends upon particle size,particle concentration, and the brine contentof the water in the case oflatex emulsions. Threshold values are best determined experimentally bynoting the surfactant level at which a given particle dispersion beginsto form films at the air-water or water-soil interfaces. This point isreached before coagulation occurs in the bulk solu tion away from suchinterfaces.

For equal throughput of the same particle content, the quantity ofparticle solids deposited per unit pore volume will depend upon twofactors: (I) the surfactant present in excess of the thresholdrequirement; and (2) the specific surface area of the porous medium.Specific surface areas can vary from square meters per gram for clays toless than one square meter per gram for coarse sand. Practicalsituations give rise to varied and specific surface values as they existat the application site. Since these, values cannot be controlled, thesurfactant levels therein must be controlled and adjusted to prepareparticle suspensions and dispersions which will penetrate virtually anymatrix which has pores substantially larger than the terminal particlesize. For example, in sealing coarse sands or other large-grainmaterials, which have low specific surface areas, one should operate ator close to the threshold surfactant levels with little or no excesssurfactant present. For a given initial particle concentration, thiswill yield a relatively heavy deposit of particle solids per unit areaof internal mineral surface. Heavy deposits can be tolerated in coarsesand applications, without completely suppressing penetration, becauseof the large pores available for flow. However, in finegrained media,with large specific surface areas and smaller pores, heavy deposits areexcessive and prevent any significant penetration.

As discussed hereinabove, the ultimate (equilibrium) quantity ofparticle solids deposited per unit pore volume depends primarily uponthe ratio between stabilizing surfactants and suspended solids ratherthan upon their absolute concentrations. The same ultimate solidsdeposition, by using either a small volume of concentrated particlesuspension or a large volume of dilute suspension as long as thesurfactant to solid ratio were held constant, would be achieved.Practical considerations will require that particle solids content asapplied normally be confined to a range between about 1 and percent byweight and preferably limited to the range between about 2 and 6 percentby weight.

A preferred embodiment of the present invention is in the use of latexdispersions wherein the latex is a brine-coagulatable natural orsynthetic material. Synthetic latexes are available through modernemulsion polymerization processes which yield aqueous dispersions, orlatexes, of polystyrene, polybutadiene, styrene-butadiene copolymers,and many other polymeric elastomer latexes. Over the wide range ofcommercial latexes, average particle diameters vary from about 0.03 toabout 1.0 microns and terminal (largest) particle diameters vary fromabout 0.1 to about 10 microns. For any one selected latex, the

in Table II hereinbelow. The type identifications listed below in TableI are ASTM designations as recognized by the art.

Asphalt emulsions can be achieved using nonionic surfactants, withaverage particle diameters of about 2 microns and terminal particlediameters of about 6 microns. These special purpose asphalt emulsionscan be utilized by the process of our invention for mediumto-course soilapplications.

The method of our invention can be illustrated in various ways as willbe seen from the following examples and tables. Examples I and Ildemonstrate the invention through the use of a buried, perforated pipesurrounded with unconsolidated soil. The results as shown in Table 11were achieved through the application of a soil-filled vertical glasstube.

EXAMPLE I A dispersion of 5,000 ppm (0.5 weight percent) of SBR 2101latex solids in 50,000 ppm (5.0 weight percent) brine was stabilizedwith 1,000 ppm nonylphenoxypoly(ethyleneoxy)ethanol (lgepal CO-6l0)nonionic surfactant, while the pipe was buried in a container ofunconsolidated sand, sealing solution was injected into a dead end,one-inch pipe which had 10 (5tinch) holes drilled through its sides.Prior to latex injection, water poured onto the sand invaded the pipethrough the holes at a rate of about 150 milliliters per minute. Afterone latex injection the water influx was reduced to less than 0.5milliliter per minute, a reduction of about 99.7 percent in invasionrate. The seal was distributed over a distance of about 4 inches fromeach hole.

TABLE I Description of Types of Styreno/BntzulimnRubin-r (SH It) andBntndieno/Rubber (B R) Latexes Percent (,ontninml Nominal polynwrn-siduul Nominal Nominal noin. Mooney vol. nn- Nominal coagulum NominalNominal Nominal Aeti Short- Catn- Entulconv., vista. .\ll. sntnrntv,1111 on No. 80 hound total Type t0mp., F. vzitor stop lyst sion pvrt-vnt1+1 L212 1".) percent vnluv sieve 1 styrene solids S13R2l01 13 FRA N1)OIll FA (it) n 0.1 11.0 0.10 23.5 21 SB R 2lll [*RA ND Olll R11 52 0. 1021.5 0.10 23. 5 20 S13 1t 2112.. 50 l RA NI) ()lll RA tit] 52 0,10 J. 50.10 23. 5 40 l U.S. Sieve Series No. 80. Detailedrequirements for thissieve aregivcn 1n tln- SDttllittlllOllS for Sivrvs l'or 'ltSllllgPurposes (ASTAI Designation: E 11), 1061 Book 01' ASTAI Standards, Part.1.

aforementioned range is much more narrow than those establishedhereinabove.

A commercially available latex dispersion, for example, could haveexcess surfactant which places dispersion beyond threshold values. Thisexcess surfactant concentration can be manipulated through the additionof weak sodium chloride solutions in place of fresh water for dilutionpurposes. These weak brine solutions normally contain from about 1 toabout 2 percent sodium chloride. The sodium chloride content raises thethreshold surfactant requirement until it matches the requirementsestablished by soil conditions.

Exemplary of the preferred brine-latex emulsions of this inventioninvolve styrene/butadiene-rubber and butadiene/rubb'er latexes found inTable 1 below. Both examples as found in Table I below were used intesting the process of this invention which is further illustrated NorliAbbreviations and symbols used in this table are defined as follows:FA=Fntty Acid. FRA Fruv Radical Type, N1)=Nondiscoloring, t)lll=t)rganicHydro Pvt-oxide, RA=R0sin Acid.

EXAMPLE II A dispersion of 10,000 ppm SBR 2101 latex solids in freshwater was established with 500 ppm ofnonylphenoxypoly(ethyleneoxy)ethanol (lgepal CO-7l0) nonionicsurfactant. The same perforated pipe apparatus described in Example Iwas again emresults of several tests made in accordance with the processof our invention. Table II illustrates primarily the preferredembodiment, that being the brine-latex emulsion approach, but alsoincludes an asphaltic in response to contact of the emulsion with thesoil and adsorbtion of the surfactant by the soil for sealing said soil.

2. A process according to claim 1 wherein the latex duit and through thesurrounding soil in contact therewith for coagulating the emulsion inthe soil emolsion f p T contents of Table II were particles are selectedfrom the group consisting of achieved uslng a vertically mounted glasstube about 1 Styrene/butadiene mbber and butadiene/mbber Inch dlamotefand from "lobes long, equipped 3. A process, as set forth in claim 1,wherein the with retaining screens or fritted glass discs at thebotemulsion contains brinetom end. Each tube was packed about half fullo 4. A process according to claim 3 wherein the sodieonsfhdated Porousmeda dlfferent gram sues um chloride concentration is less than 20,000ppm. rangmg from. ultra'fine claysm mixtures up to very 5. A processaccording to claim 3 wherein the soil coarse Ottawa Sands A was a at thetop of surrounding the underground conduit opening has a the packs sothat the addltlon of liquid would not grain Size off-mm about 1 to aboutmmicrons disrupt the packlng at the upper surface.The unpacked l5 Aprocess, as Set forth in claim 3, wherein the upper e of the tubesprol'lded a ma head Space of emulsion has a solid concentration of fromabout 2 to 6 mchgs h gh, thlerem prtlzovldlngl the maximum 20,000 toabout 50,000 pressure use to t e pamc 6 Slons 7. A process, as set forthin claim 1, wherein the sur- The single asphalt emulsion was a specialpreparafactantisanon-ionic surfactant, tion with a maximum particle sizeof about 6 microns. 8. A process, as set forth in claim 1, wherein thesur- This emulsion as applied contained 2500 ppm of mixed f tam isnonylphenoxypoly(ethyleneoxy)ethanol. 11001011: Surfactants Introducedduring manufoe' 9. A process for the in situ sealing of soil surroundingture. The results as obtained with the asphalt emulsion an opening i anunderground conduit, comprising; as shown in Table II y flmher indicatethat the injecting into the conduit a surfactant-stabilized preferredembodiment of our invention is the surfacemulsion, id emulsion h i b i|atex taut-stabilized, brine-latex emulsion process. Table ll C168, d rft nt h i id 1 m, ni h and its included results are for illustrativepurposes being in a size range f about 01 to about 10 y and Should notconsidered as hmltmg "P the microns and said surfactant being anon-ionic sur- Seope ofthe presentmvemloofactant of a volume sufficientfor providing the TABLE 11 Sealant cmulsioll Nominal watcr permeabilityLatex Solids NilCl Nollionie (darcys) pelle- 0011C. colic. surfactanttration Porous medium (grain size) Typo (p.p.m.) (p.p.m.) sealant BeforeAfter (in.) 10, 000 Nil 4, 000 0. 01 Nil 1. 5 Clay-Silt (ultrafine) 1.0microns SBR 2111, 21120.... 40, 000 Nil Nil 0.01 Nil 0. 1 "BR 111 211 i'g i881 i) 0 8i 2'8 Bflmsdall Sand microns R 5 fjj' jjj 01 00 10, minNil 0150 N11 0. '25 Mill Creek Sand (medium) 5v1lllC1QllS f &2? g (L012SBR 2111, 2112 40, 000 Nil 1, 000 130 10 0.0 Ottawa Sand (coarse) 10microns .Y {SB It 2101 H 20, 000 10,000 Nil 130 0.05 6.0 SBIt2101 20,000 20, 000 Nil 130 0.02 15 Ottawa Snad (coarse) 10 microns Asphalt20,000 10,000 Nil 130 40 6.0

1 Unstable in bulk.

.The results in Table II above demonstrate an effecemulsion withapreselected stability; and tive water permeability barrier ranging from0.1 up to 6 passing a volume of the emulsion through the openinches fromthe conduit break. These effective results ing in the conduit andthrough the surrounding soil primarily illustrate the application of thepreferred emin contact therewith for coagulating the emulsion bodimentof a surfactant-stabilized, brine-latex emulin the soil in response tocontact of the emulsion sion process. Certain modifications of ourinvention with the soil and adsorbtion of the surfactant by will becomeapparent to those skilled in the art and the the soil for sealing saidsoil. illustrated details disclosed hereinabove are not to be 10. Aprocess, as set forth in claim 9, wherein the considered as imposingunnecessary limitations on the emulsion is a non-ionicsurfactant-stabilized, brineinvention. containing latex particlesemulsion having a solid conwhat we claim is: centration from about20,000 to about 50,000 ppm. 1 A f h r f 11. A process, as set forth 1nclaim 9, wherein the on e m situ Sea so] mg surfactant isnonylphenoxypoly(ethyleneoxy)ethanol. PP f an undergroundcondultlFomPnsmg' 12. A process, as set forth in claim 9, wherein themlectl ng' an emulson condulPi f emulson 6() latex particles areselected from the group consisting of havmg water latex Particles of mthe range styrene/butadiene-rubber and butadiene/rubber. o about toabouf 10 and f surfaetem 13. A process, as set forth in claim 9, whereinthe an amount suffieleoe to Provlde Sald emulslon sodium chlorideconcentration is less than 20,000 ppm. Wlth a preselected stablhty; and14. A process, as set forth in claim 9, wherein the soil passing theemulsion through the opening 1n the consurrounding the undergroundconduit opening has a grain size in the range of about I to about l0microns.

V'Q-UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO.3,727,412 Dated April 1973 Inventor(s) J Marx et 1;

It is certified-that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

On the cover sheet [75] "John W. Marx; Jr. Bowman" should read John W iMarx; Mark M. Bowman, Jr.

Signed and sealed this 5th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCIHVER,IJR. 1

c. MARSHALL DANN Attestlng Officer Commissioner of v Patents USCOMM-DC60376-P69 U. 5. GOVERNMENT PRINTING OFFICE I," O-8G6-334,

FORM PO-IOSO (1069)

2. A process according to claim 1 wherein the latex particles areselected from the group consisting of styrene/butadiene-rubber andbutadiene/rubber.
 3. A process, as set forth in claim 1, wherein theemulsion contains brine.
 4. A process according to claim 3 wherein thesodium chloride concentration is less than 20,000 ppm.
 5. A processaccording to claim 3 wherein the soil surrounding the undergroundconduit opening has a grain size of from about 1 to about 10 microns. 6.A process, as set forth in claim 3, wherein the emulsion has a solidconcentration of from about 20,000 to about 50,000 ppm.
 7. A process, asset forth in claim 1, wherein the surfactant is a non-ionic surfactant.8. A process, as set forth in claim 1, wherein the surfactant isnonylphenoxypoly(ethyleneoxy)ethanol.
 9. A process for the in situsealing of soil surrounding an opening in an underground conduit,comprising: injecting into the conduit a surfactant-stabilized emulsion,said emulsion having brine, latex particles, and surfactant therein,said latex particles being in a size range of about 0.1 to about 10microns and said surfactant being a non-ionic surfactant of a volumesufficient for providing the emulsion with a preselected stability; andpassing a volume of the emulsion through the opening in the conduit andthrough the surrounding soil in contact therewith for coagulating theemulsion in the soil in response to contact of the emulsion with thesoil and adsorbtion of the surfactant by the soil for sealing said soil.10. A process, as set forth in claim 9, wherein the emulsion is anon-ionic surfactant-Stabilized, brine-containing latex particlesemulsion having a solid concentration from about 20, 000 to about 50,000ppm.
 11. A process, as set forth in claim 9, wherein the surfactant isnonylphenoxypoly(ethyleneoxy)ethanol.
 12. A process, as set forth inclaim 9, wherein the latex particles are selected from the groupconsisting of styrene/butadiene-rubber and butadiene/rubber.
 13. Aprocess, as set forth in claim 9, wherein the sodium chlorideconcentration is less than 20,000 ppm.
 14. A process, as set forth inclaim 9, wherein the soil surrounding the underground conduit openinghas a grain size in the range of about 1 to about 10 microns.